Compatible OpenGL / OpenGL ES games on i.MX6

If you happen to have an ARM development board sitting around, you may be thinking about plugging it into your nearest HDTV to play some games. While the ultimate gaming computer is probably not going to be built around a single-board computer such as ODROID or Raspberry PI, it might be interesting to see what such a device is capable of. I was looking for games that would utilize the OpenGL|ES capability provided by the i.MX6Q processor, but there aren't that many compatible Linux games out there, with most still using the standard "desktop" OpenGL. Many of the similar ARM SOCs provide only GL|ES and do not support OpenGL at all, but the i.MX6Q at least supports some part of the OpenGL 2.1 specification. To help me keep track of the results, I started creating my own "ultimate guide" for GL/GL|ES compatible games on i.MX6Q and maybe others might find this information useful as well.

In order to make my list, I require that the game will run full-screen with "reasonable" FPS, and utilize the hardware GL or GL|ES capability of the i.MX6Q (refer to my previous posts how the system is setup). However, on the Sabre Lite and SabreSD boards that I'm using, I found that many of these games don't set the video mode properly, but it can be done manually using xrandr prior to running the game. I am also trying to keep track of some different monitors that I am using (a 4:3 A/R Dell, a 1920x1080 RCA HDTV, and our new 55" Samsung HDTV), as the aspect ratio may affect what modes are available to the game.

As I mentioned in the introduction above, I found only a couple of games so far that are using GL|ES graphics on Linux, these are:

• Trigger Rally, ported to OpenGL|ES by ptitSeb (libGLES_CM)
• Hurrican, ported by pickle (libGLESv2)

The i.MX6Q supports at least a part of OpenGL 2.1 and I have found a half dozen or so titles that are compatible, including an early version of Neverball. I have found quite a few more games that will run if linked to a special implementation of libGL called glshim. The glshim library was devised by lunixbochs for the purpose of "providing OpenGL 1.x functionality to OpenGL ES accelerated cards" (and thus to to expand the available games for the Pandora ... and possibly other platforms). As stated glshim provides "parts of OpenGL 1.x by internally translating to OpenGL ES". By now, glshim has found its way from the Pandora world to other ARM platforms such as Odroid, and i.MX6. I am using the ptitseb branch as I found it would allow a few games to run that the lunixbochs version wouldn't, but at this time I have not bothered to see what the functional differences are between the two versions.

Running the game executable with glshim may be as simple as invoking it with LD_CONFIG_PATH. However, I seem to find that I have to re-link the executable, else it tends to defer to the libGL.so which is already installed on my system. This is easily done be replacing '-lGL' with e.g. '/usr/local/lib/glshim/libGL.so' in the link command.

One final comment is that out of the dozen or so games that I have built and found working with glshim, all are using libSDL-1.2, with the exception of CaveExpress (libSDL2-2.0). 

Enjoy!